Organization of the Indian hedgehog--parathyroid hormone-related protein system in the postnatal growth plate.
Organization of the Indian hedgehog--parathyroid hormone-related protein system in the postnatal growth plate.
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DOI：
10.1530/jme-10-0177
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发表时间：
2011-08
影响因子：
3.5
通讯作者：
Nilsson O
中科院分区：
文献类型：
--
作者：
Chau M;Forcinito P;Andrade AC;Hegde A;Ahn S;Lui JC;Baron J;Nilsson O
在胚胎生长软骨中，印度刺猬（Ihh）和甲状旁腺相关蛋白（PTHrP）参与调节软骨细胞分化的负反馈回路。出生后，该区域经历了重大的结构和功能变化。为了探索出生后生长板中Ihh-PTHrP系统的组织，我们将7日龄大鼠的生长板显微解剖成其组成区，并评估参与Ihh-PTHrP反馈回路的基因表达。Ihh、Patched 1、Smoothened、Gli 1、Gli 2、Gli 3和Pthr 1在与胚胎生长软骨中的表达结构域类似的区域中表达。然而，PTHrP在静止区软骨中表达，该部位不同于胚胎来源，即关节周围细胞。然后，我们使用小鼠，其中lacZ已经取代了Gli 1的编码序列，从而作为活跃的刺猬信号的标记。在1，4，8，和12周龄，lacZ的表达检测到的模式类似于胚胎软骨。研究结果支持这一假设，即胚胎IHH-PTHrP反馈回路维持在出生后的生长板，除了PTHrP的来源已转移到一个更近端的位置在休息区。
In embryonic growth cartilage, Indian hedgehog (Ihh) and parathyroid hormone-related protein (PTHrP) participate in a negative feedback loop that regulates chondrocyte differentiation. Postnatally, this region undergoes major structural and functional changes. To explore the organization of the Ihh–PTHrP system in postnatal growth plate, we microdissected growth plates of 7-day-old rats into their constituent zones and assessed expression of genes participating in the Ihh–PTHrP feedback loop. Ihh, Patched 1, Smoothened, Gli1, Gli2, Gli3, and Pthr1 were expressed in regions analogous to the expression domains in embryonic growth cartilage. However, PTHrP was expressed in resting zone cartilage, a site that differs from the embryonic source, the periarticular cells. We then used mice in which lacZ has replaced coding sequences of Gli1 and thus serves as a marker for active hedgehog signaling. At 1, 4, 8, and 12 weeks of age, lacZ expression was detected in a pattern analogous to that of embryonic cartilage. The findings support the hypothesis that the embryonic Ihh–PTHrP feedback loop is maintained in the postnatal growth plate except that the source of PTHrP has shifted to a more proximal location in the resting zone.